Electricity + Control July 2018

round up

FLOW MEASUREMENT + INSTRUMENTATION

Temperature profiling and logging at its best Measuring product time at temperature in heating applications has been an accepted industry practice for decades. The earliest temperature profiling systems plotted data on a chart that process engineers had to laboriously analyse. Today, profiling systems that are both sophisticated and easy to use can give a clear pass/fail finding. Temperature profiling is the term used to describe the process of recording and interpret- ing the temperatures of products through a heating process. Temperature data is measured continuously using thermocouples connected directly to the product at different locations as it travels through the oven or furnace. The measured temperature readings are stored in a data logger, which moves along with the product and is protected from the hostile environ- ment of the process by a thermally insulated box referred to as a thermal barrier. Either during the process (using telemetry) or post-process, the profile data is retrieved from the data logger and transferred to a computer software package where it can reviewed and analysed. Temperature data collected from the profiling operation provides a graph/pro- file showing what temperatures the product or oven experienced during the entire heating procedure. Such information creates a thermal fingerprint of the product and process, which is critical to the understanding of the heating operation. In its simplest form, this informa- tion tells you how hot your product became, the time it took to get there, and how long it stayed at that temperature. Process engineers know what the perfect profile for their product should be; variations from the ideal indicate a potential problem that can lead to or unacceptable product quality. Control product quality Increased scrap, rework or customer returns means something has gone wrong in your manufacturing operation. If you know precisely what is happening to your products during production, you can easily reduce rejects, rework, scrap and returns. Rapidly setup new processes Routine monitoring of your process establishes a database of profile information, which will help you develop new processes accurately and efficiently. You’ll know exactly what tempera- ture settings and line speeds will result in the best quality product. Find faults quickly When a problem occurs because of improper heating, you’ll quickly spot the cause and lo- cation. Then, you can analyze the profile information to determine the necessary corrective action, and run follow-up profiles to prove the changes were successful. Increase productivity Analysis of temperature profiles will also show how and where you can optimize operations. By rebalancing the time at temperature and heat ratios, you may be able to increase line speed and product throughput. And by knowing exactly what is happening to your product in your process, you’ll be able to minimize time spent on test runs and process setups – allowing a greater number of profitable production runs. Prove process control (QS/ISO9000)

Level measurement in buffer and production silos

VEGAPULSE 69 fromVEGA Instruments offers a cost effective, user friendly and maintenance-free non-contact level measurement solution for buffer and production silos. After crushing and screening, the different aggregates are transported via conveyor belts and dis- tributed among the silos. Before further processing, the stones, gravel or rock flour are stored in buffer and production silos. To ensure optimal material stor- age, a precise level measurement is re- quired. VEGAPULSE 69 provides a relia- ble measurement, independent of dust, abrasion and product moisture content. Enquiries: Chantal Groom. Email chantal.groom@vega.com The LMC family of sensors from ifm re- liably monitors levels in machine tools or wastewater management, and also protects pumps from running dry. The option of a thread at the back of the monitor permits variable installation depths and application-specific instal- lation. The LMC sensor can be set to almost any liquid or viscous medium as well as to bulk materials. Permanent medium temperatures up to 100°C or a heavy build-up are no problem. The dif- ferentiation between two media is pos- sible due to the two switching outputs, which can be set independently. The parameters can be set with IO-Link and USB interface accessory E30390. Enquiries:Tel. +27 (0) 12 450 0400 or email info.za@ifm.com Maintenance-free level detection

A profiling system, combined with a well-designed software package, will go a long way to assist in reporting process control adherence to author-

ities and customers. Minimise fuel costs

Rising fuel costs can significantly im- pact your operating budget. Informa- tion retrieved from profiling, can help cut down on excessive heat settings. Lower fuel costs mean higher profits, and reduced fuel consumption has a positive environmental impact. Enquiries: R&C Instrumentation. Tel. +27 (0) 11 608 1551 or email sales@randci.co.za

42 Electricity + Control

JULY 2018